JP4122141B2 - Hybrid vehicle drive control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drive control device for a hybrid vehicle, and more particularly to a device for reducing a shock at the time of clutch engagement when a command to switch to running by an internal combustion engine is issued during running by an electric motor.
[0002]
[Prior art]
An internal combustion engine, an electric motor connected to the output shaft of the internal combustion engine via a clutch, and a wheel connected to the output shaft of the electric motor and input at least one of the output torque of the internal combustion engine and the electric motor for shifting In a hybrid vehicle equipped with an automatic transmission that drives the vehicle, when the accelerator pedal is depressed during travel by an electric motor and the driver indicates an intention to accelerate, the clutch is engaged to switch to travel by an internal combustion engine. .
[0003]
However, in that case, if the internal combustion engine is simply started and the clutch is engaged, the engine output torque is added to the motor output torque, and the vehicle drive torque changes suddenly, which may shock the passenger.
[0004]
Therefore, in the technique described in Japanese Patent Application Laid-Open No. 2000-23312, a second electric motor is provided in preparation for the start of the internal combustion engine, and the output torque of the internal combustion engine is absorbed by the second electric motor, It has been proposed to reduce the shock by controlling the motor rotation speed to coincide.
[0005]
More specifically, in this prior art, the output torque of the second electric motor when the output torque of the internal combustion engine is absorbed is detected, the engine output torque is estimated, and the difference between the detected torque and the estimated torque is calculated. Based on this, the target torque of the electric motor connected to the automatic transmission is corrected.
[0006]
[Problems to be solved by the invention]
However, since it is difficult to accurately estimate the output torque of the internal combustion engine, the above-described prior art cannot always reduce the shock sufficiently. Furthermore, since it is difficult to predict the behavior of the clutch transmission torque, the above-described prior art is not always sufficient in terms of control response to an instantaneous torque change.
[0007]
Accordingly, an object of the present invention is to eliminate the inconveniences described above, an internal combustion engine, an electric motor connected to the output shaft of the internal combustion engine via a clutch, an internal combustion engine connected to the output shaft of the electric motor, Shock at the time of clutch engagement in a hybrid vehicle having at least an automatic transmission that drives wheels while shifting by inputting at least one output torque of the electric motor when switching to traveling by an internal combustion engine during traveling by the electric motor It is an object of the present invention to provide a drive control device for a hybrid vehicle that can reduce the above.
[0008]
[Means for Solving the Problems]
In order to solve the above-described object, in claim 1, an internal combustion engine, an electric motor coupled to an output shaft of the internal combustion engine via a hydraulic clutch, and an output shaft of the electric motor are connected. In a drive control device for a hybrid vehicle that includes an automatic transmission that inputs an output torque of at least one of the internal combustion engine and the electric motor and drives the wheels by shifting the input torque. A start control means for starting the internal combustion engine and supplying a preparatory pressure to the hydraulic clutch when starting to switch to running by the internal combustion engine, and starting an increase control of an output torque of the electric motor; Engine rotational speed detection means for detecting the rotational speed of the started internal combustion engine, and supply oil to the hydraulic clutch in synchronization with the detected increase in the engine rotational speed Output increase control means for increasing and decreasing the output torque of the electric motor, and when the detected engine speed reaches a predetermined speed, while temporarily decreasing the output torque of the internal combustion engine The engine output control means for increasing the hydraulic pressure supplied to the hydraulic clutch up to the line pressure is provided.
[0009]
In this way, when switching to running by the internal combustion engine is commanded, the start of the internal combustion engine and the supply of the preparatory pressure to the hydraulic clutch are started, and the increase control of the output torque of the electric motor is started, and the detected engine In synchronism with the increase in the rotational speed, the increase control of the hydraulic pressure supplied to the hydraulic clutch and the increase / decrease control of the output torque of the electric motor are performed, and when the detected engine speed reaches a predetermined speed, the output torque of the internal combustion engine The hydraulic pressure supplied to the hydraulic clutch is controlled to increase up to the line pressure while the pressure is temporarily reduced.
[0010]
In other words, the electric motor, the hydraulic clutch, and the internal combustion engine are controlled in coordination with the detected increase in engine speed (decrease in differential rotation), and the hydraulic clutch is engaged while the engine output torque is reduced. Therefore, it is possible to reduce the fluctuation of the drive shaft torque without estimating the output torque of the internal combustion engine, thereby reducing the shock when the hydraulic clutch is engaged and reducing the load of the hydraulic clutch. be able to.
[0011]
The output increase control means sequentially compares the detected engine speed with a plurality of threshold values, and the detected engine speed exceeds the plurality of threshold values. Each time the hydraulic pressure supplied to the hydraulic clutch is increased and controlled, the output torque of the electric motor is increased or decreased.
[0012]
In this way, the detected engine speed is sequentially compared with a plurality of threshold values, and each time the detected engine speed rises above the plurality of threshold values (in other words, a plurality of differential speeds corresponding to each other). It is configured to increase the hydraulic pressure supplied to the hydraulic clutch and to increase / decrease the output torque of the electric motor (in other words, the same parameter is compared with the common threshold). As a result, the electric motor, the hydraulic clutch and the internal combustion engine are controlled so that they can be effectively coordinated, and the shock at the time of engagement of the hydraulic clutch can be achieved without estimating the output torque of the internal combustion engine. In addition to being able to reduce more effectively, the load on the hydraulic clutch can also be reduced more effectively.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
A hybrid vehicle drive control apparatus according to an embodiment of the present invention will be described below with reference to the accompanying drawings.
[0014]
FIG. 1 is a schematic diagram showing the overall drive control apparatus for the hybrid vehicle.
[0015]
As shown in the figure, this apparatus includes a four-cylinder spark ignition type internal combustion engine (hereinafter referred to as “ENG” and hereinafter referred to as “engine”) 10, and an output shaft 10 a of the engine 10 connected to an input shaft 14 a via a hydraulic clutch 12. An electric motor (referred to as “Motor”) 14 to be connected and an automatic transmission 16 connected to an output shaft 14 b of the electric motor 14 are provided.
[0016]
The engine 10 comprises OHC in-line four cylinders, and an injector (not shown) is provided in the vicinity of an intake valve (not shown) of each cylinder connected to an intake pipe (not shown) via an intake manifold (not shown). Is provided. When fuel is injected from the injector, the injected fuel is mixed with the air sucked from the intake pipe and flows into each cylinder as an air-fuel mixture.
[0017]
When the engine 10 is started, the air-fuel mixture flowing into each cylinder is ignited and burned, and a piston (not shown) is driven to rotate a crankshaft (not shown). The rotation of the crankshaft is taken out from the output shaft 10a.
[0018]
As shown in FIG. 2, the hydraulic clutch 12 is a multi-plate hydraulic clutch in which a plurality of clutch disks 12a and clutch plates 12b are alternately arranged. Reference numeral 12c denotes a hydraulic chamber, and reference numeral 12d denotes a return spring.
[0019]
When hydraulic oil (ATF) is introduced and hydraulic pressure is supplied, the hydraulic clutch 12 presses the clutch disk 12a against the clutch plate 12b, thereby directly connecting the output shaft 10a of the engine 10 and the input shaft 14a of the electric motor 14.
[0020]
The electric motor 14 comprises a DC brushless generator motor, is connected to a battery (not shown) via a motor energization circuit 18 and operates as an electric motor when energized and is driven by the engine 10 when energization is stopped. Then it operates as a generator to charge the battery.
[0021]
As shown in FIG. 1, the automatic transmission 16 includes a metal belt type continuously variable transmission (CVT) and is connected to wheels 24 via a final gear 20, a differential gear 22, and a drive shaft 23. The automatic transmission 16 receives the output torque of at least one of the engine 10 and the electric motor 14, and changes the input torque at a ratio (gear ratio) set by the hydraulic pressure supplied via the hydraulic mechanism 25 to change the wheels 24. To drive a vehicle (not shown). Note that the hydraulic pressure is supplied to the hydraulic clutch 12 through the hydraulic mechanism 25.
[0022]
A first rotational speed sensor 26 is provided in the vicinity of the output shaft 10a of the engine 10 on the upstream side of the hydraulic clutch 12, and outputs a signal proportional to the rotational speed (clutch input rotational speed) NE of the engine 10 and is electrically operated. In the vicinity of the output shaft 14 b of the motor 14, a second rotation speed sensor 28 is provided on the upstream side of the connection of the automatic transmission 16, and outputs a signal proportional to the rotation speed NM (mission input rotation speed) of the electric motor 14. .
[0023]
A throttle opening sensor 30 is provided in the vicinity of a throttle valve (not shown) of the engine 10 and outputs a signal corresponding to the throttle opening TH. Further, a water temperature sensor 32 is provided in the vicinity of a cooling water passage (not shown) of the engine 10 to output a signal corresponding to the cooling water temperature TW, and an outside air temperature sensor is provided at an appropriate position of an intake pipe (not shown). 34 is provided to output a signal proportional to the outside air temperature TA.
[0024]
An accelerator opening sensor 38 is disposed in the vicinity of an accelerator pedal (not shown) on the driver's seat floor of the vehicle, and outputs a signal corresponding to the driver's accelerator pedal depression amount AP. The accelerator pedal is mechanically separated from the throttle valve, and the throttle valve is driven independently of the accelerator pedal operation via an actuator such as a pulse motor (not shown).
[0025]
A temperature sensor 40 is provided in the vicinity of the hydraulic mechanism 25 of the automatic transmission 16 to output a signal proportional to the temperature TATF of the hydraulic oil (ATF), and a vehicle speed sensor 42 is provided in the vicinity of the drive shaft 23. An output signal proportional to the traveling speed (vehicle speed) of the vehicle is output.
[0026]
The outputs of these sensors are input to the controller 50. The controller 50 is composed of a microcomputer, detects the engine speed based on the sensor output described above, and calculates the output torque of the electric motor 14 from the energization command value to the motor energization circuit 18 of the electric motor 14.
[0027]
FIG. 3 is a flowchart showing the operation of the hybrid vehicle drive control apparatus according to this embodiment.
[0028]
Prior to the description of the figure, the background of the operation of the apparatus according to this embodiment will be described with reference to FIG.
[0029]
This operation relates to an operation when the accelerator pedal is depressed to indicate the driver's intention to accelerate and the engine 10 is instructed to switch to traveling when the vehicle is traveling by the electric motor 14.
[0030]
FIG. 4 is an explanatory diagram showing torque transmission at the time of switching. That is, when traveling by the electric motor 14 shown in FIG. 5A, the output torque of the electric motor 14 is input to the automatic transmission 16. Next, when switching to engine running is commanded, the electric motor 14 assists and the engine 10 starts to be started as shown in FIG.
[0031]
FIG. 5 is a time chart showing changes in the engine speed NE (and the motor speed NM) and the drive shaft torque Tds due to the motor assist shown in FIGS. 4 (a) to 4 (d).
[0032]
When the engine is started, if the output torque of the electric motor 14 is not controlled to be increased so as to complement (absorb) the inertia of the engine 10, the drive shaft torque Tds decreases as indicated by a broken line in FIG.
[0033]
Returning to the description of FIG. 4, as shown in FIG. 4C, when the start of the engine 10 is completed, both the output torque of the engine 10 and the output torque of the electric motor 14 are input to the automatic transmission 16, and then the hydraulic pressure When the engagement (engagement) of the clutch 12 is completed, only the output torque of the engine 10 is input to the automatic transmission 16 via the output shaft of the electric motor 14 as shown in FIG.
[0034]
When the engagement of the hydraulic clutch 12 is completed, as shown in FIG. 5, the drive shaft torque Tds changes suddenly by the amount of the inertia supplement torque of the electric motor 14, which may give a shock to the occupant as described above.
[0035]
Therefore, in the operation of the apparatus according to this embodiment, as shown in the time chart of FIG. 6, the electric motor 14, the hydraulic clutch 12, and the engine 10 are configured to be cooperatively controlled to reduce the above-described shock. At the same time, the load on the hydraulic clutch 12 is reduced by reducing the fluctuation of the output shaft torque.
[0036]
The operation of the apparatus according to this embodiment will be described below with reference to the flowchart of FIG.
[0037]
First, in S10, the start of the engine (ENG) 10 is determined according to the switching command described above. That is, when the electric motor 14 travels and the temporal change amount of the output of the accelerator opening sensor 38 is greater than or equal to a predetermined value, the driver intends to accelerate, as shown in the upper part of FIG. A switching signal (command) from traveling by the engine 14 to traveling by the engine 10 is issued, and the start of the engine 10 is determined accordingly, and timer 0 (up counter) is started to start time measurement.
[0038]
Next, the process proceeds to S12, where the preparation pressure is supplied to the hydraulic clutch 12 (hydraulic supply). That is, as shown in the clutch pressure command value of FIG. 6, energization to an electromagnetic solenoid (not shown) is started so that the hydraulic pressure supplied to the hydraulic clutch 12 has characteristics as shown. This preparatory pressure supply is a hydraulic pressure supply corresponding to so-called invalid stroke filling. Specifically, as shown in FIG. 7, a command is given through energization to the electromagnetic solenoid so that a predetermined time tp0 and a predetermined height P1 are obtained. To do.
[0039]
More specifically, the predetermined time tp0 and the height P1 are parameters related to the viscosity of the hydraulic oil ATF, and are the clutch rotational speed (the hydraulic clutch 12 detected based on the output of the first rotational speed sensor 26). The number of revolutions) is determined based on the temperature TATF of the NCL or hydraulic oil ATF according to the characteristics shown in FIG. 8 or FIG. 9 so as to improve the response of the hydraulic clutch 12 and optimize the invalid stroke filling.
[0040]
Next, the process proceeds to S14 and waits for the value of timer0 to exceed the predetermined time t0. The predetermined time t0 is a dead time that is appropriately set according to the cranking characteristics of the engine. Specifically, as shown in FIG. 10, the predetermined time t0 is set to decrease as the water temperature TW indicating the warm-up state of the engine 10 increases. Is done. In place of the water temperature TW, the temperature TATF of the hydraulic oil ATF may be used.
[0041]
When the elapse of the predetermined time t0 is confirmed in S14, it is determined that the cranking of the engine 10 has started with the assistance of the electric motor 14, and the process proceeds to S16, S18, S20 and the electric motor 14, the hydraulic clutch 12 and the engine 10 are Take control.
[0042]
For simplification of explanation, although shown in one flow chart, the processing from S16 to S20 is actually executed simultaneously (synchronously) in parallel in separate routines. In addition to the above, control of the automatic transmission 16 is also performed, but it is omitted because it is not directly related to the gist of the present invention.
[0043]
FIG. 11 is a subroutine flowchart showing the control of the electric motor 14.
[0044]
In the following, in S100, the current motor torque equivalent energization command value MT is set as the motor torque command value MT0. The motor torque command value is calculated as an energization command value for the motor energization circuit 18. Specifically, the processing in this step calculates a motor torque equivalent value estimated to be output from the electric motor 14 from the energization command value. It means to replace it with that value.
[0045]
Next, in S102, it is determined whether or not the differential rotation dN is less than a threshold value dN2 (for example, 1000 rpm). The differential rotation dN is obtained by subtracting the engine rotation speed (detected based on the first rotation speed sensor 26) NE from the motor rotation speed (rotation speed of the electric motor 14 detected based on the second rotation speed sensor 28) NM. In this control, as shown in FIG. 6, since the motor speed NM is controlled to be constant, the differential speed dN indirectly indicates the engine speed NE. Therefore, the above is equivalent to determining whether the engine speed NE has increased beyond the amount corresponding to the threshold value.
[0046]
When the result in S102 is negative, the program proceeds to S104 where the addition term MTCU1 is added to the motor torque command value MT0 to increase the correction, and the same processing is repeated until the result returns to S102 and affirmed. That is, as shown in the time chart of FIG. 6, the motor output torque is increased at a constant rate until dN becomes less than dN2 (in other words, the engine speed NE increases correspondingly).
[0047]
When the result in S102 is affirmative, the program proceeds to S106, in which it is determined whether or not the differential rotation dN is less than a second threshold value dN5 (for example, 50 rpm), and when the result is negative, the program proceeds to S108 and the motor torque command value MT0 is set to the second value. The addition term MTCU2 is added to increase the correction, and the process returns to S106 and the same processing is repeated until affirmative.
[0048]
Therefore, as shown in the time chart of FIG. 6, the motor output torque TM is kept constant until dN becomes less than dN2 and then becomes less than dN5 (in other words, the engine speed NE increases by that amount). Increase in proportion. Note that the second addition term MTCU2 <the addition term MTCU1 is set, and the motor output torque TM is controlled so that the increase rate after becoming less than dN5 is smaller than the increase rate until becoming less than dN5. This is because the inertia of the engine 10 has been absorbed when it becomes less than dN5.
[0049]
When the result in S106 is affirmative, the program proceeds to S110, in which it is determined whether or not the motor torque command value MT0 exceeds the third threshold value tm0 (shown in FIG. 6). The subtraction term MTCD1 is subtracted from the value MT0 to reduce the motor torque command value, and the same processing is repeated until the result returns to S110 and negated.
[0050]
Subtract term MTCD1 >> addition term MTCU1 (and second addition term MTCU2) (in absolute value), thereby reducing dN below dN5 and below threshold tm0 as shown in the time chart of FIG. The motor output torque TM is rapidly decreased at a constant rate until
[0051]
When the result in S110 is negative, the program proceeds to S114, where it is determined whether or not the motor torque command value MT0 is 0 (shown in FIG. 6). When the result is affirmative, the program is immediately terminated. Then, the second subtraction term MTCD2 is subtracted from the motor torque command value MT0 to reduce the motor torque command value, and the same processing is repeated until the determination returns to S114.
[0052]
As in the case of addition, the second subtraction term MTCD2 << subtraction term MTCD1 is set, and after being less than the threshold value tm0, in other words, it becomes extremely small compared to the reduction rate until it becomes less than tm0. If so, the motor output torque TM is controlled so as to gradually decrease.
[0053]
Next, clutch control will be described.
[0054]
FIG. 12 is a subroutine flow chart showing the control of the hydraulic clutch 12. The hydraulic clutch 12 is in a state where the supply of the preparation pressure has been completed by the processing described in S12 of the flowchart of FIG.
[0055]
In the following description, in S200, the value P0 is defined as a clutch pressure command value (command value defined by the energization amount to the electromagnetic solenoid of the hydraulic clutch 12) PCL. Similar to the motor torque command value, the clutch pressure command value is also calculated as an energization command value for the electromagnetic solenoid.
[0056]
The value P0 means a pressure corresponding to the initial set load of the return spring 12d of the hydraulic clutch 12, and is specifically calculated as follows.
P0 = FRTN / APST
In the above, FRTN: load of the return spring 12d, APST: piston area of the hydraulic clutch 12.
[0057]
Next, the routine proceeds to S202, where it is determined whether or not the differential rotation dN is less than a fourth threshold value dN1 (eg, 1200 rpm). If the determination is negative, the routine proceeds to S204 where the addition term CLCU1 is added to the clutch pressure command value PCL to increase. The same process is repeated until it is corrected and the process returns to S202 and affirmed. That is, as shown in the time chart of FIG. 6, the clutch supply hydraulic pressure is increased at a constant rate until dN becomes less than dN1.
[0058]
When the result in S202 is affirmative, the routine proceeds to S206, where it is determined whether or not the differential rotation dN is less than a fifth threshold value dN4 (for example, 100 rpm). Then, the second addition term CLCU2 is added to the clutch pressure command value PCL to correct the increase.
[0059]
Therefore, as shown in the time chart of FIG. 6, after dN becomes less than dN1, it is held at a constant value until it becomes less than dN4, and after dN becomes less than dN4, the clutch supply hydraulic pressure becomes constant again. Increase at a rate of. Note that the second supply term CLCU2> the addition term CLCU1, and the rate of increase after being less than dN4 is larger than that until it becomes less than dN1, in other words, the clutch supply hydraulic pressure increases rapidly. To control.
[0060]
Next, the routine proceeds to S210, where it is determined whether or not the clutch pressure command value PCL has become equal to or greater than the line pressure equivalent value (shown in FIG. 6). Until it is done, the process returns to S208 and the same processing is repeated.
[0061]
As described above, in this control, the increase control of the hydraulic pressure supplied to the hydraulic clutch 12 (clutch pressure command value) and the output torque of the electric motor 14 are synchronized with the detected decrease in the differential rotation (increase in the engine speed NE). Increase / decrease control of (motor torque command value) is performed.
[0062]
More specifically, a plurality of detected differential rotations dN (a value obtained by subtracting the engine rotation speed NE from the motor rotation speed NM and indirectly indicating the engine rotation speed when the motor rotation speed NM is constant) are plural. A comparison is sequentially made with the threshold value dNn.
[0063]
The hydraulic pressure supplied to the hydraulic clutch 12 (clutch pressure command value) every time the detected differential rotation becomes less than the threshold value (in other words, the engine speed NE increases by an amount corresponding thereto). The output torque TM (motor torque command value MT0) of the electric motor 14 is controlled to increase or decrease.
[0064]
Next, engine control will be described.
[0065]
FIG. 13 is a subroutine flow chart showing the control of the engine 10.
[0066]
Although not shown, the engine 10 is cranked and started by transmitting the rotation of the electric motor 14 when the preparation pressure is supplied to the hydraulic clutch 12 and the invalid stroke is reduced.
[0067]
In the following, in S300, the process waits until the differential rotation dN becomes less than the sixth threshold value dN3 (for example, 150 rpm).
[0068]
When it is confirmed at S300 that dN is less than dN3, the routine proceeds to S302, where the ignition timing is retarded by a minute amount (minute crank angle) and dQ retarded (retarded). In other words, this engine control is intended to temporarily reduce the output torque of the engine 10, and the ignition timing is retarded from that intention. At this time, in order to avoid a sudden change in the engine output torque, when the differential rotation dN becomes less than dN3, as shown in FIG. 14, a small amount dQ is retarded as compared with an original retardation amount QTRTD described later.
[0069]
Next, the process proceeds to S304, waits for the differential rotation dN to be close to dN3 and less than the fifth threshold value dN4, and if it is confirmed that dN is less than dN4, the process proceeds to S306 and timer1 (up counter ) Is started to start time measurement, and the process proceeds to S308, where the ignition timing is retarded (retarded) by a predetermined amount (predetermined crank angle) QTRTD.
[0070]
Next, in S310, it is determined whether or not the value of timer1 exceeds a predetermined value (time) trtd (shown in FIG. 14), and a predetermined amount of retardation is continued until affirmative. Thereby, the output torque of the engine 10 is greatly reduced. The retard amounts dQ, QTRTD and the time trtd are values according to the intended reduction amount of the engine output. Further, a crank angle may be used instead of the time trtd.
[0071]
When the result in S310 is affirmative, the program proceeds to S312 and the ignition timing is returned to the advance direction by an amount corresponding to the retard amount QTRTD, and the program proceeds to S314 and the ignition timing is similarly returned to the advance direction by a small amount dQ. End.
[0072]
The above description will be made with reference to FIG. 6. When the detected differential rotation dN (a value indirectly indicating the engine rotational speed NE) becomes less than the threshold value dN3 (predetermined rotational speed), the engine output When the torque TE starts to decrease and becomes less than the subsequent threshold value dN4, the hydraulic pressure supplied to the hydraulic clutch 12 is increased to the line pressure (line pressure equivalent value) while greatly reducing the engine output torque TE. .
[0073]
As described above, in this control, the electric motor 14, the hydraulic clutch 12, and the engine 10 are cooperatively controlled in synchronization with the detected decrease in the differential rotation (increase in the engine speed NE).
[0074]
That is, the contents of control of the electric motor 14, the hydraulic clutch 12, and the engine 10 are switched by comparing the same parameter (differential rotation dN) with a common threshold value dNn (dN1, 2, 3, 4, 5). I did it.
[0075]
Referring to the time chart of FIG. 6, until dN becomes less than dN2, the motor output torque is monotonously increased in order to absorb the inertia accompanying the start of the engine 10, while dN is set near dN2. The clutch supply hydraulic pressure is increased rapidly until it becomes less than dN1.
[0076]
Next, after dN becomes less than dN2, it is considered that the absorption of the engine inertia has been completed, and the motor output torque TM is similarly monotonously increased at a smaller increase rate until dN becomes less than dN5. When the NM approaches less than dN3, the ignition timing of the engine 10 is slightly retarded, and when it becomes less than dN4, the ignition timing is retarded by the original predetermined amount to greatly reduce the engine output torque TE. Then, the clutch supply hydraulic pressure is rapidly increased to a value corresponding to the line pressure, and the hydraulic clutch 12 is completely engaged.
[0077]
At the same time, since the motor output torque is not required when the clutch is engaged, the motor output torque is rapidly decreased to a value near tm0, then gradually decreased to zero, and the delay angle is also unnecessary.
[0078]
With this configuration, as shown in the time chart of FIG. 6, the characteristics of the motor output torque TM can be made smooth, and fluctuations in the drive shaft torque Tds can be reduced. Accordingly, it is possible to reduce the shock at the time of engaging the hydraulic clutch 12 without estimating the output torque TE of the engine 10, and to reduce the load on the hydraulic clutch 12.
[0079]
FIG. 15 is a time chart showing a simulation result of the control (operation) of the hybrid vehicle drive control apparatus according to this embodiment, and FIG. 16 is a time chart showing the simulation result when such control is not performed. It is a chart.
[0080]
As is clear from the comparison between FIG. 15 and FIG. 16, in the case of FIG. 16, the fluctuation amount of the drive shaft torque Tds was about 100 kgfm, whereas in the apparatus according to this embodiment, about 5 kgfm. Decreased.
[0081]
Further, the drop in clutch transmission torque and motor output torque TM seen in FIG. 16 does not occur in FIG.
[0082]
As described above, this embodiment is connected to the internal combustion engine (engine 10), the electric motor 14 connected to the output shaft 10a of the internal combustion engine via the hydraulic clutch 12, and the output shaft 14b of the electric motor. Drive control of a hybrid vehicle including an automatic transmission (CVT) 16 that inputs the output torque TE, TM of at least one of the internal combustion engine and the electric motor and drives the wheels 24 by shifting the input torque. When the apparatus (controller 50) is instructed to switch to running by the internal combustion engine during running by the electric motor, start of the internal combustion engine and supply of preparatory pressure to the hydraulic clutch are started (S10, S12). The start control means (S16, S100 to S108) for starting the increase control of the output torque of the electric motor is started Engine speed detection means (first and second engine speed detection means) for detecting the speed of the engine (engine speed NE, more specifically, a speed dN obtained by subtracting the engine speed NE from the electric motor speed NM). Output speed control means (S16) for performing an increase control of the hydraulic pressure supplied to the hydraulic clutch and an increase / decrease control of the output torque of the electric motor in synchronism with the detected increase in engine speed. , S18, S100 to S116, S200 to S210), and when the detected engine speed reaches a predetermined engine speed (dN4), the output torque of the internal combustion engine is temporarily decreased while the hydraulic clutch is applied. The engine output control means (S18, S20, S304 to S314, S206 to S210) for increasing the supply hydraulic pressure to the line pressure is provided.
[0083]
The output increase control means sequentially compares the detected engine speed with a plurality of threshold values (dNn), and the detected engine speed increases exceeding the plurality of threshold values ( In other words, each time the differential rotation decreases below a corresponding threshold value, the supply hydraulic pressure to the hydraulic clutch is increased and the output torque of the electric motor is increased / decreased (S16, S100 to S116). It was configured as follows.
[0084]
In the above, the ignition timing is retarded to reduce the engine output torque. However, the engine output torque may be reduced by stopping the fuel supply (fuel cut (FC)). May be.
[0085]
In the above description, the CVT is used as the automatic transmission. However, a stepped transmission may be used. The electric motor is not limited to the DC motor, and may be an AC motor.
[0086]
【The invention's effect】
According to the first aspect of the present invention, when switching to running by the internal combustion engine is instructed, the start of the internal combustion engine and the supply of the preparatory pressure to the hydraulic clutch are started, and the increase control of the output torque of the electric motor is started. In addition, in synchronization with the detected increase in the engine speed, the increase control of the hydraulic pressure supplied to the hydraulic clutch and the increase / decrease control of the output torque of the electric motor are performed, and when the detected engine speed reaches a predetermined speed, The engine is configured to increase the hydraulic pressure supplied to the hydraulic clutch to the line pressure while temporarily reducing the output torque of the internal combustion engine.
[0087]
In other words, the electric motor, the hydraulic clutch and the internal combustion engine are coordinated in synchronization with the detected increase in engine speed, and the hydraulic clutch is engaged while reducing the engine output torque. Without estimating the output torque, it is possible to reduce the fluctuation of the drive shaft torque, thereby reducing the shock at the time of engagement of the hydraulic clutch and reducing the load of the hydraulic clutch.
[0088]
According to claim 2, the detected engine speed is sequentially compared with a plurality of threshold values, and the hydraulic pressure supplied to the hydraulic clutch is increased each time the detected engine speed exceeds the plurality of threshold values. In addition to controlling, the output torque of the electric motor is configured to increase / decrease, in other words, the same parameter is compared with a common threshold value to control the electric motor, the hydraulic clutch, and the engine 10. They can be effectively coordinated, and the shock at the time of engagement of the hydraulic clutch can be reduced more effectively without estimating the output torque of the internal combustion engine, and the load of the hydraulic clutch is also more effective Can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall drive control apparatus for a hybrid vehicle according to an embodiment of the present invention.
2 is an explanatory perspective view showing in detail the structure of the hydraulic clutch of the apparatus of FIG. 1. FIG.
FIG. 3 is a flowchart showing the operation of the apparatus of FIG. 1;
4 is an explanatory diagram showing torque transmission at the time of switching from running by an electric motor to running by an internal combustion engine in the apparatus of FIG. 1. FIG.
5 is a time chart showing changes in engine speed, drive shaft torque, and the like during torque transmission in FIG. 4;
6 is a time chart showing the overall operation of the apparatus of FIG.
7 is a time chart showing the characteristics of clutch preparation pressure in the flow chart of FIG. 3. FIG.
8 is an explanatory graph showing characteristics with respect to the clutch rotational speed NCL, such as the preparation pressure holding time tp0, among the characteristics of the clutch preparation pressure shown in FIG. 7;
9 is an explanatory graph showing characteristics with respect to the hydraulic oil temperature TATF such as the preparation pressure holding time tp0 in the characteristics of the clutch preparation pressure shown in FIG. 7;
FIG. 10 is an explanatory graph showing characteristics of a predetermined time (dead time) in the flowchart of FIG. 3;
FIG. 11 is a subroutine flowchart of motor control in the flowchart of FIG. 3;
12 is a subroutine flowchart of clutch control in the flowchart of FIG. 3;
FIG. 13 is a subroutine flowchart of engine control in the flowchart of FIG. 3;
FIG. 14 is an explanatory graph showing a retard amount of the ignition timing in the flowchart of FIG. 13;
15 is a time chart showing simulation results for the operation (control) of the apparatus of FIG. 1. FIG.
16 is a time chart showing a simulation result when the operation (control) of the apparatus of FIG. 1 is not performed. FIG.
[Explanation of symbols]
10 Internal combustion engine
12 Hydraulic clutch
14 Electric motor
16 Automatic transmission (CVT)
18 Motor energization circuit
26 First rotational speed sensor
28 Second rotational speed sensor
50 controller

Claims (2)

An internal combustion engine; an electric motor coupled to the output shaft of the internal combustion engine via a hydraulic clutch; and an output torque of at least one of the internal combustion engine and the electric motor connected to the output shaft of the electric motor. In the drive control device for a hybrid vehicle provided with an automatic transmission that drives the wheels by shifting the input torque,
a. When switching to running by the internal combustion engine is commanded during running by the electric motor, start of the internal combustion engine and supply of preparatory pressure to the hydraulic clutch are started, and increase control of output torque of the electric motor is started. Starting control means to
b. Engine speed detecting means for detecting the speed of the started internal combustion engine;
c. Output increase control means for performing increase control of the hydraulic pressure supplied to the hydraulic clutch and increase / decrease control of the output torque of the electric motor in synchronization with the detected increase in the engine speed;
And d. An engine output control means for increasing the hydraulic pressure supplied to the hydraulic clutch to a line pressure while temporarily reducing the output torque of the internal combustion engine when the detected engine speed reaches a predetermined speed;
A drive control apparatus for a hybrid vehicle, comprising: The output increase control means sequentially compares the detected engine speed with a plurality of threshold values, and supplies hydraulic pressure to the hydraulic clutch every time the detected engine speed exceeds the plurality of threshold values. 2. The drive control apparatus for a hybrid vehicle according to claim 1, wherein the output torque of the electric motor is controlled to increase / decrease.

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